Gas-generating device utilizing a chemical composition candle



May 13, 1969 J. w. MAUSTELLER 3,443,907

GAS'NERATNG UlVC UTlLlZlNU A CHEMICAL COMPOSITION CANDLE Filed July 28.1966 United States Patent O 3,443,907 GAS-GENERATING DEVICE UTILIZING ACHEMICAL COMPOSITION CANDLE John W. Mausteller, Evans City, Pa.,assignor to Mine Safety Appliances Company, Pittsburgh, Pa., acorporation of Pennsylvania Filed July 28, 1966, Ser. No. 568,656 Int.Cl. B01j 7/00; C01h 13/00 U.S. Cl. 23-281 7 Claims ABSTRACT F THEDISCLOSURE A chemical composition candle having embedded therein a pairof metal contact members, at least one of which is a prong projectingfrom one end. The contact members are electrically connected to anigniter in the candle. The candle is placed in a housing having anoutlet for gas liberated by the burning candle. An end wall of thehousing is provided with an electric socket receiving the prong when thewall is placed on the housing to close it.

This invention relates to devices for generating gas, and moreparticularly to the production of oxygen by burning sodium chloratecandles.

One way of producing oxygen for breathing purposes is to burn a chloratecandle that gives off oxygen. To ignite the candle, it has been thepractice to embed a starting cone in it and to ignite the cone by meansof a small coil of fine wire in the cone or by an electrically actuatedchemical squib implanted in the cone. It also has been the practice toconnect the ignition wires to larger wires that extend out through thewall of the container through a ceramic seal soldered into the wall.This arrangement has made it difficult to mount the candle in itshousing and to replace it with a new candle after use. Also, the wiresconnecting the igniter with the outside circuit have interfered witharranging filtering material in the housing for filtering the oxygenproduced.

It is among the objects of this invention to provide a gas-generatingdevice of the candle type, in which the candle can be quickly and easilyinserted in its housing and removed therefrom, and in which there are nowires that interfere with the oxygen filter.

In accordance with this invention, a gas-generating candle is placed ina housing provided with an end wall and with a gas outlet. An electricalconnector is secured to the end wall and is provided with a socket thatopens toward the opposite end of the housing. An electric igniter isembedded in the candle. A metal prong projects from an end of thecandle. Also, a metal contact member projects from the candle. Thecontact member and prong are electrically connected with the igniter.The prong is slidably mounted in the connector socket in contact withthe electrical connector. The contact member engages a conductingsurface. with which the housing is provided and which, along with theelectrical connector, is adapted to be connected in an electric circuitto supply current to the igniter.

The invention is illustrated in the accompanying drawings, in which FIG.l is a plan view;

FIG. 2 is a side View;

FIG. 3 is an enlarged longitudinal section taken on the line III-III ofFIG. 2;

FIG. 4 is a cross section taken on the line IV-IV of FIG. 3; and

FIGS. 5 and 6 are reduced fragmentary longitudinal sections of twodifferent modifications.

Referring to FIGS. 1 to 4 of the drawings, a candle housing 1 has an endwall 2 that can be permanently at- 3,443,907 Patented May 13, 1969 ICCtached to the rest of the housing or, as shown, be a removable closure.This closure can be attached to the housing in various ways, such as bya suitable clamp 3. The housing also is provided with a gas outlet,which preferably is an opening 4 in the center of the opposite end ofthe housing. Only one end wall of the housing needs to be removable.Disposed inside the housing is a candle 5 of sodium chlorate or thelike, which, for best results, is spaced from the side wall of thehousing by spacing members, such as parallel rods 6 attached to theinner surface of the housing.

It is a feature of this invention that after the candle has beeninserted in the housing while the end closure is removed, attachment ofthe closure to the housing again will automatically connect the candlewith electrical connectors that readily can be connected in an externalelectric circuit for igniting the candle. Accordingly, a pair ofparallel stiff metal prongs 8 are embedded in an end of the candle, fromwhich they project a short distance. Each of them is connected by a wire9 to an electrically operated igniter 10 embedded in a starting cone 1lthat is molded into the candle. The candle is inserted in the housingwith the prongs located at end 2. To receive the projecting ends of theprongs, a pair of electrical connectors are rigidly secured to thehousing end closure and are provided with sockets into which the prongsextend. At least one of the connectors may be formed from a socketmember 12 of insulating material extending through an opening in theclosure and sealed therein. Inside the socket there is a metal contact13 or clip engaged by the adjoining prong and connected to an electriclead 14 extending out of the outer end of the socket member, in which itis sealed. The other electrical connector can be made in the same way.or it can be simply a metal socket member 15 engaged by a prong andrigidly mounted in the closure member, which is grounded when it isdesired to ignite the candle.

With this construction, it will be seen that after the candle has beeninserted in the housing the closure 2 is placed over the exposed end ofthe candle with the two electrical connector sockets in line with theprongs, and then the closure is pushed down on the prongs and housingand clamped in placed. Of course, there is a sealing ring 17 between theclosure and the housing. When the closure member and lead 14 areconnected in an external circuit, electric current flows through the twoelectrical connectors and prongs to ignite the candle so that it willstart to generate oxygen.

It is highly desirable that the oxygen leaving this apparatus befiltered. For this purpose the outlet 4 of the housing is connected witha filter in a lter case. Preferably, the filter case is in the form of acup 20 that receives a filter cartridge 21, which is held in place by ascrew cap 22 on the case. The cap is provided with one or more openings23, through which oxygen can escape after being filtered. The inlet ofthe filter case preferably is connected with outlet 4 of the candlehousing by means of a short rigid tube 24 welded to both.

The candle should be spaced from the outlet end Wall of the housing, aswell as from the side wall. One way of doing this is to mold anotherpair of prongs 26 in the end of the candle opposite the first pair.These additional prongs serve merely as spacers.

It will be seen that after the candle has been consumed the housingclosure can be removed, the residue dumped out of the housing, a newcandle dropped into the housing, and then the closure reattached. Theseare simple and easy operations. No wires have to be spliced inside thehousing and there are no wires to interfere with filtering. The mere actof putting the housing closure in place electrically connects the candleto the outside of the housing.

In the modification shown in FIG. 5 one metal prong 3l, extending out ofa candle 32 and electrically connected by a wire 33 to the starting cone34, projects into an insulating socket member 35 mounted in theremovable closure 36 of the candle housing 37 as before. Inside thesocket the prong engages a metal contact 38 that is connected to a wire39 leading out of the socket member. Unlike the first embodiment of theinvention, this modification is not provided with a second socketmember. Instead, the second metal prong 40 extends entirely through thecandle but projects only a short distance from its upper end so that awire 41 can connect it to the starting cone. The lower end of the prongprojects from the bottom of the candle and engages the lower wall of thecandle housing. In use, the housing is grounded so that there is anelectric circuit through both prongs to the starting cone.

A still further embodiment of the invention is illustrated in FIG. 6.Here again the removable closure member 45 of a candle housing 46 isprovided with only one electrical connector having a socket 47 forreceiving a metal prong 48 projecting from the upper end of the candle49. This prong is connected by a wire 50 to the starting cone 51. Theother prong or rod S2 projects just far enough from the top of thecandle to be connected by a wire 53 to the starting cone. Rigidlyattached to the upper end of this rod is a spring metal clip 54 that isengaged by the housing closure when the latter is put in place. Thestarting cone therefore is grounded against the housing, as in the formof the invention shown in FIG. 5. An advantage of these last twoembodiments of the invention is that only one electrical connector needsto be mounted in the housing end wall.

According to the provisions of the patent statutes, I have explained theprinciple of my invention and have illustrated and described what I nowconsider to represent its best embodiment. However, I desire to have itunderstood that, within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically illustrated anddescribed.

I claim:

l. Gas-generating apparatus comprising a housing provided with an endwall and with a gas outlet, an electrical connector rigidly secured tosaid end wall and provided inside the housing with a socket that openstoward the opposite end of the housing, a gas-generating chemicalcomposition candle removably disposed inside said housing, an electricigniter embedded in the candle composition, a metal prong embedded inthe candle composition and projecting from an end of it within theperiphery of the candle, a metal contact member embedded in the candlecomposition and projecting from it, and means electrically connectingsaid igniter with said contact member and prong, said prong beingslidably mounted in said socket in contact with said electricalconnector, said housing being provided with a conducting surface engagedby said contact member, and said surface and electrical connector beingadapted to be connected in an electric circuit to supply current to saidigniter.

2. Gas-generating apparatus according to claim 1, in which said contactmember is a spring contact engaging an inside surface of the housing.

3. Gas-generating apparatus according to claim 1, in which said contactmember is a second Prong projecting from the end of the candle oppositeto said lirst-mentioned prong.

4. Gas-generating apparatus according to claim 1, including a filter,and means connecting said outlet with the filter.

5. Gas-generating apparatus according to claim 1, in which said contactmember is a second prong projecting from the same end of the candle assaid rst-mentioned prong, and said conducting surface is the innersurface of a second socket carried by said housing end wall, and furtherincluding means projecting from the end of the candle opposite saidprongs for spacing the candle from the adjacent end of the housing.

6. Gas-generating apparatus according to claim 1, in which said end wallis removable and said outlet is in the opposite end of the housing, afilter case is connected with the outer end of said outlet, and a filteris removably disposed in said case.

7. Gas-generating apparatus according to claim 6, in which said housingand case are rigidly connected together by a short tube forming apassage from said housing outlet.

References Cited UNITED STATES PATENTS 3/1966 Brooks 23-281 XR 10/1966Moni et al. 2 3-281 U.S. Cl. X.R. 23-221; IGZ-70.2

